Carcinoma is a malignant epithelial neoplasm which invades surrounding tissue and metastasizes to distant regions of the body. Transitional cell carcinoma is a malignant, usually papillary tumor derived from transitional stratified epithelium, which occurs most frequently in the bladder. Most tumors in the collecting system of the human body are transitional cell carcinomas.
In order to diagnose transitional cell carcinoma in the bladder, it is necessary to do a biopsy. A biopsy is the removal of a small sample of living tissue from an organ, such as the bladder, for microscopic examination to confirm or establish a diagnosis, estimate prognosis, or follow the course of a disease. Biopsies are invasive procedures, and are therefore not desirable as it is necessary for a person undergoing biopsy to undergo anesthesia. In addition, as with any invasive procedure, an individual undergoing biopsy runs the risk of infection. Further, the entire bladder cannot be biopisied to determine whether bladder cancer is present. Biopsy procedures often require individuals to be admitted into hospitals. Alternatively, urinary cytology analysis can be performed to diagnose transitional cell carcinoma of the bladder. However, urinary cytology analysis is a time-consuming procedure, which is not always accurate. Therefore, a need exists to develop a method of diagnosing and screening for carcinoma, including transitional cell carcinoma of the bladder, as well as for monitoring cancer activity and determining the prognosis of an individual having bladder cancer.
Scatter factor has previously been described as a cytokine which is secreted by fibroblasts (see Stoker et al., J. Cell Sci., Vol. 77, pp. 209-223 (1985) and Stoker et al., Nature (London), Vol. 327, pp. 238-242 (1987)) and by vascular smooth muscle cells (see Rosen et al., In Vitro Cell Dev. Biol., Vol. 25, pp. 163-173 (1989)). Scatter factor has been shown to disperse cohesive epithelial colonies and stimulate cell motility, proliferation and morphogenesis. In addition, scatter factor has been shown to be identical to hepatocyte growth factor (HGF) (see Weidner et al., Proc. Nat'l. Acad. Sci. USA, Vol. 88, pp. 7001-7005 (1991) and Bhargava et al., Cell Growth Differ., Vol. 3, pp. 11-20 (1992)), which is an independently characterized serum mitogen (see Miyazawa et al., Biochem. Biophys. Res. Commun., Vol. 169, pp. 967-973 (1989) and Nakamura et al., Nature (London), Vol. 342, pp. 440-443 (1989)). Scatter factor induces kidney epithelial cells in a collagen matrix to form branching networks of tubules, suggesting that it can also act as a morphogen (see Montesano et al., Cell, Vol. 67, pp. 901-908 (1991)).
Scatter factor (HGF) is a basic heparin-binding glycoprotein consisting of a heavy (58 kDa) and a light (31 kDa) subunit. It has 38% amino acid sequence identity with the proenzyme plasminogen (see Nakamura et al., Nature (London), Vol. 342, pp. 440-443 (1989)) and is thus related to the blood coagulation family of proteases. Its receptor in epithelium has been identified as the c-met proto-oncogene product, a transmembrane tyrosine kinase (see Bottaro et al., Science, Vol. 251, pp. 802-804 (1991) and Naldini et al., Oncogene, Vol. 6, pp. 501-504 (1991)).
Scatter factor has been found to stimulate endothelial chemotactic and random migration in Boyden chambers (see Rosen et al., Proc. Soc. Exp. Biol. Med., Vol. 195, pp. 34-43 (1990)); migration from carrier beads to flat surfaces (see Rosen et al., Proc. Soc. Exp. Biol. Med., Vol. 195, pp. 34-43 (1990)); formation of capillary-like tubes (see Rosen et al., Cell Motility Factors, (Birkhauser, Basel) pp. 76-88 (1991)) and DNA synthesis (see Rubin et al., Proc. Nat'l. Acad. Sci. USA, Vol. 88, pp. 415-419 (1991)). In addition, preliminary studies have suggested that scatter factor induces endothelial secretion of plasminogen activators (see Rosen et al., Cell Motility Factors, (Birkhauser, Basel) pp. 76-88 (1991)).
Structurally, scatter factor is not related to the classic growth factors but is a member of the family of kringle-containing proteins. This family is characterized by triple disulfide loop structures (kringles) that mediate protein:protein and protein:cell interactions. Other kringle proteins include plasminogen, prothrombin, urokinase, and macrophage-stimulting protein. Although scatter factor is structurally related to plasminogen, it lacks proteolytic activity because of two amino acid substitutions at the catalytic center of its .beta.-chain.
Scatter factor disrupts intercellular junctions and stimulates random motility, directed migration, invasion, and production of proteases required for invasion in various human carcinoma cell lines. The inventors determined that scatter factor switches on a program of cellular activities for carcinoma-related activities. Further, scatter factor is a very potent inducer of angiogenesis, a process required for tumor growth and dissemination.
It is therefore an object of this invention to provide a method of diagnosing transitional cell carcinoma of the bladder by determining the level of scatter factor in the urine of an individual.
It is another object of this invention to provide a method of screening for transitional cell carcinoma of the bladder by determining the level of scatter factor in the urine of an individual.
It is yet another object of this invention to provide a method of monitoring the course of bladder cancer in an individual having bladder cancer by determining the level of scatter factor in the urine of said individual.
It is a further object of this invention to provide a method of determining the prognosis of an individual having bladder cancer by determining the level of scatter factor in tumor extracts from said individual.